1 files changed, 11 insertions, 0 deletions
diff --git a/lib/libc/string/strcspn.c b/lib/libc/string/strcspn.c
new file mode 100644
index 00000000..9f1f2bcd
--- /dev/null
+++ b/lib/libc/string/strcspn.c
@@ -0,0 +1,11 @@
+#include <string.h>
+
+size_t strcspn(const char *s1, const char *s2)
+{
+	size_t len = 0;
+	while (*s1 != '\0' && strchr(s2, *s1) == NULL) {
+		s1++;
+		len++;
+	}
+	return len;
+}